Rotary steam engine



June 4, l929. w. D. BAL'LERSTEDT ,ROTARY STEAM ENGINE 6 Sheets-Sheet l Filed May 20, 1924 Mr/we'ss June 4, w. D. BALLERSTEDT, 1,715,490

' ROTARY STEAM ENGINE 1 Filed May 20, '1924 6Sheets-Sheet 2 V fag. 4

' iNVE NTOR Wmunm D.BALLERSTEDT I'TNESSB. 1% gaf qwgm. 4

June 4, 1929- ,w. D. BALLERSTEDT 7 1,715,490

I ROTARY STEAM ENGINE Filed May 20, 1924 -6 Sheets-Sheet 3 rage} I I INVENTOR MLL/flMflBILLERST'DT wm W e? I J1me 1929- w. D. B'ALLZERSTEDT .7

ROTARY STEAM ENGINE Filed May 20, 1924 6 Sheets-Sheet INVENTOR Jlme 1929, w. D. BALLERSTEDT ,7

' ROTARY STEAM ENGINE Filed May 20, 1924 6 Sheets-Sheet 6 INVE NTO R W/ LlflMD-BHLLERSTED7 MTA/Esw: t 0M *ammM h WW- Patented June 4, 1929.

Parent DSTAT-Efi wILtIAM 1). BALLERSTI-ED'I, or Los ANGELEISQCALQIFOIRNIA. Y

I I ROTARY ST AM I ENGINE,

Application filed May 20,

4 This invention relatesjto cut off steam engines of the rotary type. I I An object of this invention 1s to provide a .l 'otary 'engine operable by (iXPfillSlVG fllllCl,

and adapted to isolate chargesof such fluid between the inlet andoutlet ports, and to use the expansion of such isolated fluid to revolve the rotor of suchmotor. I I I I II Another object is to avoid any applicat on to the rotor of back pressure from the expanforming a working flt at its heel with the; abutment, and with thecircularwall of the] An object is to provide a rotary engine in which the energy of an isolated charge of expansive medium is utilized to drive the motor independently of :the source. of supply throughout a considerable portion of a-revolution of the rotor after the expansive charge has been cut 'off'from the supply.

The invention isbroadly new,'basic and pioneer in various features among whichare the following: v I I In this invention a rotor in a cylinderis provided with a swinging piston the heel of which is pivoted to the rotor and fitted'to the circular cylinder wall, and the swinging endof which piston is connected to a link thatjis arranged to swing on a center that is excen'tric to the rotor; the parts being so arranged that movement; of the free end of the piston, operates throughthe resolution'of forces, to advance the rotor. I I 3 Another'pioneer feature resides in the cornlet; of a" rotor provided with a peripheral abutment, and having a working fit with the walls of the cylinder pistons, each adapted to swingon an axiseccentric to the rotor, and

cylinder, and adapted on its outer face to conform to the circular wall of the cylinder with a working fit when the piston is fully swung outward, and'toconform to-the forward side of the abutment when'the piston-is fully swunginward; and a link, the inner endjof which is arranged torevolve about an axis eccentric to the cylinder chamber; the heel of said swinging piston being pivoted to" the rotor and constructed, adapted and ar ranged to cooperate with the abutment and with the wall of thecylinder to isolate charges of the expansive medium in rapid succession. I I I I I An ob]ect is to provrde-"a rotary engine adapted to long life and ready repair, andto power is produced.

11924.1 Serial No 714,555,

this end I provide case'hardened bearings for the heels of the pistons, which'are practically nonsubject to wear and which are constructed in combination with the other parts, so that they can be easily and quickly replaced in case Another Object isto o'nstruct a rotary freely'withoutengine that the rotor can work loss of expansive medium.

Another'object is simplicity-in construetion and operation;

Features of invention are .s'how'nin the construction, combinatlon and arrangement of parts whereby a compact'e'ngine'iof great Another object is to'makeprovision for uti- .lizing the pressure ofthe expansive medium to balance the rotor.

Abroad and pioneer feature of the invention liesin rotor 'ca'rryingpistons andlixed the impel fluid at first acts atthe periphery to drive abutments; and means" whereby ling the abutments forward androtate the rotor and to move the pistoninward with" like result; and means whereby infr'egular oourseripheral side'of the abutments, to theinner sideoftheabutmentsb Another feature resides in a rotor having arrangedbetween circular walls arranged to the impelling fluid istransferred fromthe perespectively,

peripheral abutments,*and swinging pistons fit a cylinder and'p'rovided with portsand passages or Ways to a'dmitexpansive medium from the peripheries of the wallsto the space between the walls; said walls'ha'ving lateral ports for exhaust of expanded medium from. opposite sidesf of the rotorand the-oylinder having exhaust ports, ways orpfassages oppoa.

sitely arranged to allow exhaustaof the gex panded medium intermittently asthe ports of the piston pass the exhaust'ou'tlets, I

Other objects, I advantages and features of invention may appear from the accompanying drawings, the SUbJOI IIBd detail descrip tion and the appended claims.

"The accompanying drawings illustratefthe lnventlon 1n theform at present preferred,

with four pistons, to theswinging ends'of which the characters a, 6,0 and dare invention, a portion of one cylinder head being broken away to show a part ofthe ex haus t- 'port; broken lines indicate the shaft I V I I applied" in, the order in which steam has been ap elevation ofv aisteami and the anti-friction bearing the-ere; and.

' also the eccentric pin.

S Fig. 2 is an elevatlon of theintake and ex- 7 haus't' side of theengine lookingat the right -mrtted, to, an abutment to drive the motor side of Fig. 1.

' Fig. *3is an ,end elevation omitting'the" cylinder head shown in Fig. 1. The trans.-

fer channel and the final exhaust passage at the-further side of. the engine areindicated in broken lines. 1

Fig. 4 is a view off/the cylinder and workand to the piston (Z, following such abutment; to swing the piston inwardly to revolve the rotor, while an; isolated expansive cha-rge operates against the preceding piston c'to .swing it inwardly to rotatethe rotor; thenext preceding piston 5 receiving steam between its inside-face and its abutment and the steam behind the next preceding piston .a being open to the exhaust. V The anti-friction bearings are omitted fromthis view.q

' Fig. 4t? is, a view showingthe cylinder in section online ,wt-mi Figs. 2, 9 and 10,and-

showing the pistons, the abutments and links in outline; portions being broken away to expose parts otherwise hidden; and broken linesindicating other features not exposed in this view. The rotor isshown with the piston at (Z in steam taking position and near the cutoff position before the close of its inward expansion stroke; the pi'stonat 1s shown at the end of its inward; stroke; the piston at b is'show-n' at the beginning of its exhaust stroke and the piston at a between exhaust and intake positions.

Fig. is a broken sectional view on line mfi'Fig. 4 showing the inlet port Fig. 6 is a fragmental detail in section on line as, 4 showing the exhaust outlet.

and oneof the'balancing valves; arrows indicatetheexhaust flow.

F ig..7 isafragmental detail partly in section,on line @707, Fig. .6, showingthe exhaust passage and the direction of flow of theexhaust.

. Fig. 8 isasect-ion 'on line wf m fl Figs. 2, 9, and'lO, showing the different positions of the pistons and the operation of the out, offs.

The lar e arrow lndicates the direction of rob tation.

. parts otherw se hidden. 1 1

Broken lines are employed. to show The pistonat a in. this view is well along on its inward stroke, the piston at (Z has finished,

, its inward-strokesthe piston at o is started 011 1165OUtWZLldfiWiIlg with'an equalization of-pressure on itsinner and outersides; an the piston at b is exhausting. V 1 Fig.9 isa section on line or, Fig.8. j

. Fig. 10. is a section on line m em Fig. 8.

, v i, Fig. 1.1 is a view of'one of the case hardened knuckle bushes.

Fig. 12 is a quarter turn view of the knucklebush shownin Fig. 11.

ing parts in position when steam is first'ad- Fig.13 is atransverseseetion ofthe'knuckle" bush on line x Fig. 12. Fig. 14 is a longitudinal section on line as; Figrloof one of the-swinging pistons.

Fig.15is a view of the inner face of the swinging piston shown in Fig. 14.

V Fig. 16 is a central longitudinal section of one of the stationary, abutments detached} .Fig. 17 is a;s'ection on line w ,'Fig; 16,

looking toward the outer end of its abutment.

Fig. 18 is an edge view of a link for con-.

neoting the swinging end of one of the pistons I to the eccentric pin.

Fig. 19 is a side view of Fig.18. r

Fig. 20 is an edge view. of a link for conthe link shown nesting the swinging end ofa second piston to the eccentric pin.

- Fig. 21 is a side vlew of the link shownin Fig.20.

Fig. 22 is anedge view of a link for connecting the swinging; end of a. third piston to the eccentric pin.

Fig. 23 is aside View of thelink shown Fig. 22.

Fig.24 is an edge view of a link for-con necting the swinging end of a fourth piston to the eccentricpm.

Fig. 25 is a side view of the link shown in r Fig. 24. f

Fig. 26' is an enlarged fragmentalplan,

.oular chamber 3 and has peripheral inlet't at one sidejof said chamber and an expansive medium transferring way. 5 open to the circular chamber 3 and extending partly around the inside peripheralcircular. wall 6 of the rec cylinder chamber. on theside opposite' the inletA, A. rotor'T is arranged to revolve inslde the chamber and COmPHSGS'CHCUlRI 611d walls 8. 8, which are spaced apart and. 1113-.

ted to thecircular wall6 of-the cylinder and are adapted to rotate insaid cylinder on an axis 9 centralthereto and provided with ob- V lique 'abutments 10 fixed. to and revolving with the rotor and conformingat the outer ends to the circular chamber. A shaft 11 connected to said rotor and extends centrally from one end'wall ofthe rotor through one head of the cylinder. Pistons 12are pivoted at-their heels by pivots 13 to the rotor, adjacent the outer ends of the abutments .respecc tively and haveswinging ends'13 that are v movable towardand from the-circular cylin der-avall;' and said pistons are adapted on their outer sides to'conform to said circular wall, and are arranged to be swung inwardly from said wall responsive to expansive pressure between the wall and the pistons, and

. are connected to revolve about an axis 15 eccentric to the cylinder chamber so that when the abutments' 10 are revolved around the,

axis of the cylinder, the swinging ends 13 of the pistons will yield to pressure between said pistons respectively and the circular'wall of the chamber. Eccentric axis 15 is so arranged relative to the axis 9 of'rotor 7, and to the peripheral inlet 4:, that the links 14L will operate as moving struts to cause the swinging ends 13 of the pistons to approach the peripheral wall 6 of the cylinder as said ends approach the peripheral inlet 4, and so that when a piston is acted upon by an expensive medium admitted to the cylinder through the inlet at, the inward movement ofthe swinging end of the piston yielding to the 'pressure of such medium, will be accommodated by a circular movement of the rotor; and the pres sure upon the piston 12 will be translated by .25.

F or convenience of construction the abut ments are shown'as made independently of the rotor end walls, and are fixed to said end walls by suitable means as the bolts 19.

The peripheral wall 20 and the rear wall,

21 of each abutment are closed to thesteam admitted at the intake 4 tothe space or pocketlfi between the swinging pistons and theperipheral wall 6 of the chamber, so thatwhen the steam orother expansive medium enters at 1, it will act upon the rear face ofv the abutment, and between the peripheral wall and the swingingpiston; and will swing the piston inward while the impact of the steam on the abutment will' be effective in conjunction with the pressure upon the" swinging piston, to rotate the rotor; and the expansion of theniedium continuesto force the swinging end of the piston inward after the knuckle preceding the outer end of the abutment has in Fig. 4.

The space between the end of the inlet 4 and the beginning. of the transfer passage 51s. greater than the distance between the heel -13 of the swinging piston 12 and the rear face 21 of the abutment with which the swinging end 13 of said piston cooperates to form a pocket for-retaining the steam between the piston, the circular wall and the rearward the passed the inlet 4:, as indicated face of the abutn ent and' the inner face of the swingingpiston "and the outer face. of its companion abutment, jare conformed to each other so that owing to the eccentricity of the axis on which the links 14 swing, the revolv ing rotor brings the lateral port 18 ofthe abutment intoposition' to open the ports 17 to the. lateral'extensions 16 ofi the transfer passage 5.'- The pistons are arranged as shown in Fig. 8 to'close the outlet 125 from the passage 18 as by means of-a: valve port1on 23 oflthe swing ng PlStOD; and. as the rotor revolves theport 18 is opened as indicated at 2 1 in Fig- 8. I v v I, Said piston 12 isprovided Wltll an intermediate passage 25. adapted to transfer the expansivemedium from outside the piston to the space 26 between the outer side of they abutment 10 and 'the'inner face of the swing-( ing piston 12., This occurs at the time when themoving strut thrusting link, as at 14: is 7 beginning to move the piston toward the pe riphery; and at a time whenthe piston, asat 17 is beginning to star t towardthe curved wall 6 of the chamber; and the steam thus admitted into the space between the abut ment and the-swinging plstonequalizes the: pressure on the outer and nner faces of the 7 piston and expands between the inner face of thes winging piston; and the outer face of the abutment. I The rotor is provided with-a number of exhaust ports 27 that extend through the side wallsof the rotor andare sopositionedtha't as the rotor revolves to a position wherelthe steam in the inner. expansion chamber 26, is

entirely expanded, and the outer surfacoof;

the piston is fitted against the wall of the cylinder, the exhaust poi-t2? of the rotor will open to an exhaust passage 28, leading through a head of the cylinder to the exhaust pipe29. l/Vhen the rotor walls are in a position so that the passage 18 is opened to the lateralextension 16 of the transfer passage ;5,the inner end of the passage'18 is closed-by the forward end 23 of t'he piston. -.2

haust port 28 in the cylinder wall, the port 27 5 port 28 and said ports 27 and 28, and the links I 1 1 and eccentric 30 are so arranged in con in. the wall of the rotorregisters with said junction with each other, that as the rotor re- Aseach piston aproaches and passes the exvolves in the position shown in Fig." 1?, the j exhaust is completed from the inner face of one piston and saidpiston remains extended outward-to fit the circular wall of the cylinzder, and the steamfrom intake 4r, pressing upon the precedingpiston which is at the bottom the view in Fig. fl beginstoiswing the piston n, andthe operation hereinbefore described is repeated.

-'It is understood'that any suitable fornr-of bearing eccentric to theaxis 9-may be-em ployed, and in thedrawing the eccentric;is.

shown. as. a .pin having anenlarged-threaded head 31 to screw intoa boss 32 in one head 33 of thecylinder.

Saidthreaded head 31' is provided-with a wrench'seat 34 by which the pininay be screwed'into and out of place.

' The head 33 has an inwardly projecting trun-.

nion 35 concentric to the axis 9 of the rotor, and-saidtrunnion is provided with a bore 36.

that is within theperiphery of the trunnion and is eccentric to said trunnion and to the axis o't rotation '9. r

37 indicates the bush in the bore and the pin 30 fits the'bush 37 tightly so that the pin "30 is rigidly hcl deccentric to the axis of rot-ation'oit therotor. Said pin extends across the space between the'rotor wall8 and8.

The rotor wall 8 is provided with a roller "bearing seat 38, and the anti-friction bearing 39,'1s seated in said seat and is carried by the trunnion 35'which carries the rotor head 8". a

' The links 14 are supported on'a roller bearing' iO carried bythe eccentric-pin 30. The i head of said eccentric pin is protected by a cap 41 which may serve as a chamber to supply grease to the grease duct 42 in the eccentric pin to supply grease to the rollerbearing 40. Y

The shaft 11 is shown as constructed in-.

tegral with the wall 8 of the rotor; andthe 'head 43' of the cylinder is provided with an internal boss 44 having a ball bearing chamber 45 in which an anti-friction bearing 46 is mounted to support. the shaft 11 that ex tends; through the cylinder head 43 and V a flange bushing 47, which holds packing 8 in the head.

' The rotor wall 8 is shown provided with a cavity 4:9 which may be supplied with lubricant and which is open to the anti-friction bearing 46. v

Wearing plates 50 are lctinto the'inside faces of the cylinder heads 33 and 34, and are shown secured by screws 51. f 7 Each of the links is provided with a bearing 52 on which the pistons 12 are swung.

' Saidlinks 14L are rigid and 'are 'constructed "as indicated in'Figs. 18'25 to practically close the space'betw'een the eccentric bearing and the piston, The outer ends of the links 14 are pivoted to thesw ngmg ends of the V pistons by pivots52.

"Thecylinder heads 33 and 43 have corresponding exhaust passages 28 and each passage 28 has an enlargement 53 to 'accom-l 'modate the balancing valve 54 0f a balancing screw 55 that is threaded through the cylinder head 43. lhe re are two of said balancing valves arranged diametrically oppositetof each other in the cylinder heads 33 and 14:3, and are adapted to choke or open the exhaust from the opposite ends ofthe v rotor to cause the flow or steam through the rotor to be equally discharged from opposite v i sides thereof.

Thee-joints at thepivoted ends of, the pistons'are protected by bushes 56 having cylin drical ends 57 (see Figs. 11, 12 and 13) with pintle holes 58 therethrough and a semicylindrical web wear. i The knuckle in combination with the circular wall-G. are adapted to't'orinsteam :cut

oils to isolate'the partially expanded steam so thatthe pressure can be applied to the 59 at each end. "These knucklesmay easily be made of case hardened toolfsteel and afford protection against Y swinging ends of the pistons as herein'betore explained. I

In the drawings the jpipe 4 is indicated as an ordinary pipe; butthe intake is shown as flattened to deliver the pressureentirely acrossthe space between the end walls of the 5 rotor. v i It is understood that the shape'ot the abut: ments, the pistons, the intake 4, and other pas'sages,-1nay be changed within the judgment oi the constructor, without departing fromthe spirit of this invention and I do not limit my invention to the exact shapes and forms oi' passages, ports and parts shown. It is understood that the invention maybe used as a meter and also as a pump for either liquid or expansive fluid.

By reversingthe motor it maybe operated pump. In such case-power would be" applied to the rotor shaft from an external. source of power, not shown inthe drawings.

I claim: I

1. The combination vof a cylinder having a circular chamber, a peripheral inletat one side of said Chamber, and an expansive medium,

transferrin 'wa extendin artl around the inside peripheral wall of the cylinder on the.

side'opposite the inlet; a rotor comprising cirinder; pistons pivoted to the rotor adjacent therespective ends of the abutments, and having swinging ends that are movab'le toward and from the circular cyli'n der wall, and which are adapted to conform to'said wall and to be swung inwardly-from said wall responsive to expansive pressure between such. wall and the pistons respectively; said transferring way being adapted to conductthe expansivemedicular end walls spaced apart and fitting-the um from the outside to the inside of said.

pistons; links connected to the swinging ends of the pistons and to an axis eccentric to said cylinder chamber to which saidpistons are re volvably mounted. j

2. A circular rotor comprising two walls, and .abutinents between said walls, the walls and abutments being infixed relation to each 20 I 7 medium from-one side to the. other of apiston ofthe swinging pistons during a portion other, the walls being spaced apart by the abutments, and the abutments beingspaced apart fro m each other in circular arrange ment around the axis ofthe rotor a shaft fixed to the rotor co-axial therewith; arcylinder having a'circular chamber in which the rotor is journaled concentrically to revolve; said cylinder having two-heads between which the rotor is fitted; cylindrical bearing means connected to and supportedby the cylinder and'revolubly supporting the'rotor in the cylinder; a link supporting bearing eccentric to said rotor supporting bearing;links supported by, and oscillatable relative to the rotor and link "supporting bearing;,pist ons cartried. by the rotor near the rim thereof and] adapted to swingtoward and from such rim and the vcircular wall of the cylinder, the links being pivotally connected to cooperate with the swinging pistons to supply fluid of each rotation of the rotor; and means to,

allow discharge :of fluid from between the swinging pistons and the circular wall of the cylinde tion.

r during, another part of such rota- 3. In a rotary engine a cylinder and i a rotor; an abutment fixed to the rotor and co cut off; said cylinder wall having an inlet operating with the cylinder ,wall to form a and a transfer way a swinging piston pivoted to the rotor, and cooperating with the rotor,

' theabutmentand the cylinder to form expan 5 ton on its axis asthe rotor revolves.

sion chambers on opposite sides of'the piston; and means for transferring expansive medium from one side tothe otherside of a piston for the purpose of allowing swingingofthe pis 4. The combination with a" cylinder having a circular chamber with peripheral and lateral passages for an expansible fluid; of a 10- tor having end walls spaced'apartand abutments and pistons cooperating therewith arranged between such walls; the walls of said .cylinderand rotor being providedwith pe- V ripheral and other passages adaptedtoallow .fiuid' to flow through therotor between the peripheral and lateral; passages of the cylinder to conduct the fluid from one side to the other side of saidpistons, for the purpose ofexhausting the expanding medium.

: 5. The combination with arotorcarrying swinging pistons and fixedabutments, of

means whereby an impelling mediumis caused to first act at the periphery of the: rotor-to drive the abutments forward and rotatethe rotor and to move the pistons inward with;

like result; and means whereby in regular course the impelling fluid is transferredfrom the outer sides of the abutments and pistons respectively, to the inner sides of the pistons for the purpose of exhausting theimpelling medium 7 f v i 6. The combination with a rotor carrying swinging pistons and fined, abutments, of means whereby animpelling me'dium is caused to first 'act' at the'peripher'y of the rotor to drive the abutments. forward and rotate the rotorand to move the'pisto'ns inward with like,

result; means whereby inregularcourse the t impelling fluid is transferred frorn'theflpe,

ripheral sides of the abutments,respectively to the inner side of the abutments; and means for exhausting the impelling medium,

7; Ina'motor having a'rotor carrying abut .me'nts fixedto therotor, and swinging pistons arranged tocoopera-te with thero'torand the abutments'; and means adapted to apply the movement of the swinging pistons'to'rotate,

the rotor; ,of ways through the periphery of the rotor,through theabutments and the pistons to ap'ply impellin'g medium between the-outer faces of the abutments and the ini nerfacjesiof the pistons'the'swingingends of sald p stons'berng linked to anaxis eccentric l to the axis of the rotor; andekhaustmeans 3; to allow the:ekpandedimpelling fluid "to escape from the motor/J, I i

Ina roctor-having"acylindrical her, a rotor. mounted to revolfve in said chain her andprovid'ed with abutments and pistons and'with peripheral and other ways'extend ing through the rotor walls theabutments and pistons, respectivelypand through the rotor walls to communicate-t between the spaces between the abutmentsrespectively and theirrespeeti-ve pistons toconduet the opthe other, and ways' -communi'cating between erating fluid from one Side of the pi'stonsto the outside of the cylinder and, the space unfderneath the-abutment s and the pistons and means cooperating with said lastnamed 1 ways for allowing escape of fluid.

' 9; A motor comprising acylinder having spaced apart and fitting the cylinder, said cylinder having an-intake and a transfer way,

' the intake being at one side and the transfer way at an opposite side of the cylinder; said space between the rotor walls,- and-the; rotorthe rotor being providedwith. abutments and a' circular wall; a rotor having end walls a 11o transfer way beingof. greater width than-the i i g walls, being provided with peripheral ways. I j to. communicate with the transfer way, and 1 15- swinging'pistons cooperatingtherewith, and fforming pockets; and ways in said rotor adapted to communicate with the transfer 7 er ng expansive fluid from pockets outside way of the cylinder for the purpose of. deliv -v e [i Y 120 the swingingpistonsto pockets inside the I last named ways.

der 11). which the rotor is; mounted and is real" I adapted to be refined; and which cylinder is provided with an intake to-adinitlexpansivemedium tjo-the pistons'to drive the rotor,- and With outlet means "tofallow exhaust'of expanded imedium,f-saiid cylinder having a transferway of greaterwid-th than the space be'twee nthe inner faces of the rotor walls, and

' said rotor Walls havingways'to conduct expansi've medium from "the space between v the rotor walls toward the exhaust outletl 11". A'motor of the Character se'tforthhaving a rotoripro vided with spaced apart cir' oularwalls and having abutlnents and piscylinder having an intake for impelling mei dium, and a transferred way of greater width "than the space between the inner faces of the rotor walls, and being spaced from-the intake 7 a'ndadaptedrto allowexpanded impellingmefdium to pass onward. towardfhe exhaust uwhen-the pi'stons; respectively have ended 1 the-inward'stroke.

:12. A rotary engine having inside a cylin der a rotor. havingsi dew'alls provi'dedwith wa s, "and also V having between said ways, abutments and pistons which are provided with 'passages,';ports and ways for expansive I medium; said pistonsbeing arranged com bination with other ports, to swing respon; slve to pressureo'fexpansive medlum; and also adapted to. open andIclose the passages,

ports and'ways to'lio w'of the expansive medi- 7 11m" as thfe 'rotorrevolves and means to ap- 40 i Ina motor having afcylinder and a ro tor in the cylinder; the combinatio'n ofan ply the expansive medium tothe rotorl' abutment fixedgt'o the rotor; and'a piston pivg,

otcd to the rotor and "cooperating withthe cylinder and abutment to iorma pocket"; said abutment having a lateral inlet and aport;

and said'piston having apassage oommunicat mg "with an outlet from the rotor; ofmeans operable astherotorrevolves;to-mo ve'the pisj 1 ton int o positions successivelyfor admitting practically. expanded medium "between the abutinen'tand the piston to open an outlet for such'me'dium to exhaust when the piston is in its outermost position. V v 14. The combination with a cylinder and a rotor therein adapted to be driven by expansive medium; said cylinder being proe vided with ports on opposite sides oftherotor "for discharge of expandedfmediumfrom op-.

posite sides of the rotor; means at opposite sides of the cylinder to adjust the discharge 7 'ofmedium from the rotor'for the purpose of balancing-the rotor. x V i "In witness whereof, I have here'untofset r hand at LOS e s, lifornia, this 712th d y of May, 1 924c." 1 v a v v I wIL I'A-Mn AL RS EDT.2* 

